Spring handle for percussive tools



June 3, 1930. F. A. JIMERSON 7 SPRING HANDLE FOR PERCUSSIVE TOOLS Filed Jan. 11, 1927 F H UJ R H I v INVENTOR.

y i 1' cisgfigerdon. E I :17 S AT'T EY' Patented June 3, 1930 UNITED STATES FRANCIS A. J'IMERSON, OE ATHENS, PENNSYLVANIA, ASSIGNOR TO INGERSOLL-RAN D I COMPANY, OF JERSEY CITY, NEW JERSEY, A CORPORATION OF NEW JERSEY sPRnvG HANDLE, m3 rnncnssrvn 'roons Application filed January 11, 1927. Serial No. 160,396.

This invention relates to pneumatic tools, but more particularly to a spring handle for hand held pneumatictools of the hammer.

The objects of the invention are to}protect the parts comprising the percussive element of the tool against injury, to protect the .opf struction substantially as hereinafter de-' scribed and claimed and illustrated in the accompanying drawings, in which A Figure 1 is a longitudinal sectional view of a percussive tool equipped-with a handle constructed in accordance with the practice of the invention, the handle being shown in retracted position, and

Figure 2 is the longitudinal view of a percussive tool partly broken away, illustrating the position which the handle may assume during the operation of the tool for opening the throttle valve.

Referring to the is shown embodied in a percussive tool of the coal pick type having a cylinder A in which is disposed a reciprocatory hammer piston B adapted to deliver blows to a workin implement C. The working implement in this instance extends into and is supported by the front end of the cylinder A and has a collar D which acts to limit the distance which the said implement C may extend into the cylin der. A plate E forms a closure for the rearward end of the cylinder A and on this plate E is seated a back head F which may be secured to the cylinder A in any suitable manner, such as the usual side or clamping bolts (not shown).

Disposed within the back head F is the distributing valve mechanism (not shown) but which may be housed in a valve casing G and from the rearward end of which to the front end of the cylinder A leads an inlet passage H for conveying pressure fluid to the front drawings, the invention I end of the cylinder. Similarly, an inlet passage J is formed in the plate E for conveying pressure-fluid from the front end of the distributing valve to the rearward end of the cylinder for impelling the piston B forwardly.

' In provided with a free exhaust port K about which is disposed a muffler or deflector L for deflecting the exhaust pressure fluid issuing from the exhaust port K.

Pressure fluidvfor actuatlng the hammer piston B maybe conveyed by any suitable means from asource of supply (not shown) to a passage 0 in the back'head F communicating with a'bore P in which is disposed a ball type throttle valve Q, for controlling communication between the passage 0 and a 1 passage R leading from the boreP rearwardly of the throttle valve Q to the" distributing valve mechanism. 7

- In accordance with the present invention, the back; head F is provided with a-projection S-extending in this instance in a rearward direction. Inthis projection Sis formed a continuation of the bore P, although of somewhat smaller .diametento receive slidably a Valve thepresent instance the cylinder A is stem or push rod T. The pushrod T- is preferably of such length that; its outer end will extendrearwardly of the projections when the throttle valve Q, is in its closedv position.

V In the-construction shown, a springU is disposed in the bore P toact with one end against the throttle valve Q, and with its other enol against the plugV for closing-the: throttle valveQ, whenever the pressure necessary for opening the valve is relaxed.

Novel 'means are/provided for actuating the throttle valve Q, as Well as to protect the" operator against the vibrations caused by the as i reciprocatory actionof the piston Br To this end a handle W whereby the tool may be manipu'latedis secured to a leg X of a U-shaped laminated spring Y. 7 The handle W in this instance is secured to the spring Y bymeansof rivets'Z and at th'atend of the handle into whichthespring Y is introduced is formed arecessb having inclined walls 0 above and belowthe spring Y to permit free relative movement of the spring I and the handle. It is to be understood that the exact construction of the handle W shown in Figure 1 may be departed from without violating the spirit of the invention. In other Words the inclined Walls of the recess 6 may be carried further into the handle IV. In fact the handle W may be formed as a hollow shell secured to the spring at only a small portion'of its length as far away from the curved portion ofthe' spring Y as possible. The efiect of constructing the handle IV in this manner is of course to give the spring'a greater useful length and therefore more resiliency and thus permitting the use of a rigid long wearing material such as aluminum for the handle, The opposite end (Z of the spring Y is seated on the back headF and, in the present instance, is secured thereto by means of a suitable clamping plate 6 and bolts f, only one of which is shown. i g V The handle is provided with a projection or boss'g at oneend an d in this boss is formed an aperture h to receive slidably a reduced portion j of the projection S. By thus reducing the end of the projection Sa shoulder is formed on the projection S to form an abutment for the boss g, j j

i As will be observed, when the parts comprising the handle and the throttle valve mechanism are p in thein retracted positions, there will be suff cient clearance between the handle and the push rod T to enable the throttle valve Q, to be at all times firmly pressed against its seat by the spring U.

In practice whenever necessary pressure is applied to the tool for holding it to the work, thehandleW will be pressed in the direction of the back head F, thus unseating the throttle valve Q, and admitting pressure fluid to theipercussive element of thetool, In the event that resistance to the working implement Cfshould ,ceaseas for instance when the working implement is driven into a pocket or scam in the work, thecylinder and other parts comprising the casing of the drill will jump forwardly and enable the handle W to assume its retracted position. In this way the pressure against the throttle valve Qj will be released and the spring U will then act to close the said throttle valveand shut oi the supply of pressurefluid to the cylinder A, thus preventing the piston from striking against the front end of the cylinder.

tool are almost entirely absorbed by the spring Y so that the operator will suifer less fatigue than when operating tools having the usual solid type of handle.

Iclaim: e A pneumatic percussive tool comprising a cylinc'ler and a back head, a projection on the back head having a bore, a throttle valve in thebore controlling the admission ofpressure fluid into the cylinder, a push rodegitending through said projection, a laminated spring secured "at one end' to the back head, a handle on the other end of thespring for manipulating theto'ol an'dfor cooperating with said pushrodto open the throttle valveupon the applicationjofspressuie to 'the'liandle for pressing theftoolto the 'wor kfa' boss on the handle having'anaperture to sli'dably receive the projection on the back head forgui'ding the handle, said boss forming a hood for said ection whereby detritus is eir clude dlfroin said bore, 'and a shoulder on the projection forming a stop for limiting the inward movement of the handle.

Intestimon'y wherebr-I have signed" this specification.

FRANCIS A. JIMERSON.

The present invention has been found particlllarly desirable when applied to the type oftools illustrated in the drawings. As is well known, these percussive tools are frequently used in places inwhich it is inconvenient for the operator to use both hands for manipulating the tool and this construction enables the operator to guidethe tool and control the throttle mechanism with one hand.

Afurther desirable feature of this invention is that the shocks and vibration of the 

